Receiving Apparatus, Receiving Method, Program, and Receiving System

1. A receiving apparatus comprising: reception means for receiving a code sequence coded in low density parity check and punctured at least partially as a target to be decoded; and low density parity check decoding means for performing a punctured matrix transform process including a first and a second process on an original parity check matrix noted to have punctured bits or symbols and used in the low density parity check coding, said low density parity check decoding means further performing said first process to carry out Galois field addition operations on those rows of said original parity check matrix which share non-zero elements with those columns of said original parity check matrix which correspond to said punctured bits or symbols in order to set said non-zero elements to zero, said low density parity check decoding means further performing said second process to delete the columns rid of said non-zero elements in said first process, said low density parity check decoding means further using the matrix resulting from said punctured matrix transform process as the parity check matrix for performing a low density parity check decoding process on said code sequence received by said reception means.

2. The receiving apparatus according to claim 1 , wherein said code sequence received by said reception means includes a zero-padded code sequence coded in low density parity check, and in addition to said punctured matrix transform process, said low density parity check decoding means performs a zero-padded matrix transform process to delete the columns corresponding to zero-padded bits or symbols on said original parity check matrix, said low density parity check decoding means further using the matrix resulting from said punctured matrix transform process and said zero-padded matrix transform process as the parity check matrix for performing the low density parity check decoding process on said code sequence received by said reception means.

3. The receiving apparatus according to claim 2 , wherein said code sequence received by said reception means includes code words having punctured zeros inserted through zero padding, and as part of said zero-padded matrix transform process, said low density parity check decoding means transforms said original parity check matrix into a matrix rid of the columns corresponding to the padded zeros.

4. The receiving apparatus according to claim 2 , wherein said low density parity check decoding means maintains the girth of said original parity check matrix in at least either said punctured matrix transform process or said zero-padded matrix transform process.

5. The receiving apparatus according to claim 2 , wherein said low density parity check decoding means changes the girth of said original parity check matrix in at least either said punctured matrix transform process or said zero-padded matrix transform process.

6. The receiving apparatus according to claim 2 , wherein said low density parity check decoding means maintains a minimum number of loops of said original parity check matrix in at least either said punctured matrix transform process or said zero-padded matrix transform process.

7. The receiving apparatus according to claim 2 , wherein said low density parity check decoding means changes a minimum number of loops of said original parity check matrix in at least either said punctured matrix transform process or said zero-padded matrix transform process.

8. The receiving apparatus according to claim 2 , wherein said code sequence received by said reception means is bit-interleaved, and said receiving apparatus further includes depuncture/zero depadding means for performing a depuncture and zero depadding process suitable for the matrix resulting from said punctured matrix transform process and said zero-padded matrix transform process.

9. The receiving apparatus according to claim 2 , wherein said receiver apparatus complies with DVB (Digital Video Broadcasting)-T.2, and said code sequence received by said reception means includes at least a pre-signal from among the L1 signals stipulated by said DVB-T.2.

10. The receiving apparatus according to claim 9 , wherein said code sequence received by said reception means further includes a post-signal from among said L1 signals.

11. The receiving apparatus according to claim 2 , wherein said receiver apparatus complies with DVB (Digital Video Broadcasting)-C.2, and said code sequence received by said reception means includes an L1 part-2 signal stipulated by said DVB-C.2.

12. The receiving apparatus according to claim 2 , wherein said low density parity check decoding means inhibits the process of deleting parallel processing units and the process of row transform for low density parity check decoding in said punctured matrix transform process and said zero-padded matrix transform process.

13. The receiving apparatus according to claim 2 , wherein said low density parity check decoding means does not inhibit the process of deleting parallel processing units and the process of row transform for low density parity check decoding in said punctured matrix transform process and said zero-padded matrix transform process.

14. A receiving method for use with a receiving apparatus including reception means for receiving a code sequence coded in low density parity check and punctured at least partially as a target to be decoded, said receiving method comprising the steps of: performing a punctured matrix transform process including a first and a second process on an original parity check matrix noted to have punctured bits or symbols and used in the low density parity check coding; performing said first process to carry out Galois field addition operations on those rows of said original parity check matrix which share non-zero elements with those columns of said original parity check matrix which correspond to said punctured bits or symbols in order to set said non-zero elements to zero; performing said second process to delete the columns rid of said non-zero elements in said first process; and using the matrix resulting from said punctured matrix transform process as the parity check matrix for performing a low density parity check decoding process on said code sequence received by said reception means.

15. A program for use on a computer which controls a receiving apparatus including reception means for receiving a code sequence coded in low density parity check and punctured at least partially as a target to be decoded, said program causing said computer to execute a control process comprising the steps of: performing a punctured matrix transform process including a first and a second process on an original parity check matrix noted to have punctured bits or symbols and used in the low density parity check coding; performing said first process to carry out Galois field addition operations on those rows of said original parity check matrix which share non-zero elements with those columns of said original parity check matrix which correspond to said punctured bits or symbols in order to set said non-zero elements to zero; performing said second process to delete the columns rid of said non-zero elements in said first process; and using the matrix resulting from said punctured matrix transform process as the parity check matrix for performing a low density parity check decoding process on said code sequence received by said reception means.

16. A receiving system comprising: acquisition means for acquiring over a transmission channel a signal including a code sequence coded in low density parity check (Low Density Parity Check) and punctured at least partially; transmission channel decoding means for performing a transmission channel decoding process on said signal acquired by said acquisition means over said transmission channel, said transmission channel decoding process including a process of correcting errors that may have occurred in said signal along said transmission channel, thereby obtaining and outputting an error-corrected signal; and either information source decoding means for performing an information source decoding process on the output signal from said transmission channel decoding means, or recording means for recording said output signal from said transmission channel coding device to a recording medium; said transmission channel decoding means including low density parity check decoding means for performing a punctured matrix transform process including a first and a second process on an original parity check matrix noted to have punctured bits or symbols and used in the low density parity check coding, said low density parity check decoding means further performing said first process to carry out Galois field addition operations on those rows of said original parity check matrix which share non-zero elements with those columns of said original parity check matrix which correspond to said punctured bits or symbols in order to set said non-zero elements to zero, said low density parity check decoding means further performing said second process to delete the columns rid of said non-zero elements in said first process, said low density parity check decoding means further using the matrix resulting from said punctured matrix transform process as the parity check matrix for performing a low density parity check decoding process on said code sequence acquired by said acquisition means.

17. A receiving apparatus comprising: a reception device configured to receive a code sequence coded in low density parity check and punctured at least partially as a target to be decoded; and a low density parity check decoding device configured to perform a punctured matrix transform process including a first and a second process on an original parity check matrix noted to have punctured bits or symbols and used in the low density parity check coding, said low density parity check decoding device further performing said first process to carry out Galois field addition operations on those rows of said original parity check matrix which share non-zero elements with those columns of said original parity check matrix which correspond to said punctured bits or symbols in order to set said non-zero elements to zero, said low density parity check decoding device further performing said second process to delete the columns rid of said non-zero elements in said first process, said low density parity check decoding device further using the matrix resulting from said punctured matrix transform process as the parity check matrix for performing a low density parity check decoding process on said code sequence received by said reception device.